MADISON, Wis. (AP) – The Dane County sheriff’s office says the pickup driver who struck and killed a bicyclist this week said he fell asleep at the wheel.  The collision happened Monday on a county highway near the entrance to Governor Nelson State Park in the Town of Westport.   Authorities say the pickup drifted to the right, out of its travel line, onto the paved shoulder and struck the bicyclist.  The cyclist died at the scene. The Dane County medical examiner identifies her as 37-year-old Carrie Pete of Madison.  The 21-year-old pickup driver from Waunakee was not hurt.  The sheriff’s office says the investigation remains open.